If the allegations about President Donald Trump asking then-FBI Director James Comey to stop investigating former national security adviser Michael Flynn are true, then the case would "get close to obstruction of justice," according to Sen. Tim Kaine, D-Va.

"If the facts are as they are alleged, yes, it would get close to obstruction of justice," Kaine said Wednesday on "CBS This Morning." "That is sort of a classic case that would get very close to being obstruction of justice."

"There are two facts in dispute: Did President Trump ask Comey to drop the investigation or not? That's why we need to hear from the director and from the president with all notes and tapes we can get. And second, there is a little bit of dispute about whether Director Comey had, in fact, asked for more resources before he was fired," Kaine said.

"I view firing the FBI director, and, when asked, essentially admitting, 'I'm doing it because of the Russia investigation,' if that's not an effort to impede or undermine the investigation, what is?" Kaine added.

Kaine laid out the case for obstruction of justice, saying, "You have to have an intent to obstruct, but you also have to take an action to obstruct, and the action was the firing," he said.

"The combination of asking him to drop the investigation and then firing him and citing the Russia investigation as the reason, that really completes the allegations," the senator added.

"CBS This Morning" host Charlie Rose said the show invited 20 Republican legislators and the White House to appear to discuss the issue Wednesday, but all of them declined.

If the allegations about President Donald Trump asking then-FBI Director James Comey to stop investigating former national security adviser Michael Flynn are true, then the case would "get close to obstruction of justice," according to Sen. Tim Kaine, D-Va.